1. Field of the Invention
The present invention relates to safety shoe toe caps that are applied to shoes, boots or the like to structurally reinforce the shoe toes, thereby enhancing their safety.
2. Description of the Prior Art
Regarding the toe caps in safety shoes, a great importance has hitherto been attached to the strength of the part at the upper of shoes for the protection against the dropping of a heavy material, and hence steel toe caps have been put to practical use. Since, however, safety shoes with steel toe caps are heavy, there occurs a problem with the workability of a person wearing such shoes. For this reason, in recent years, to make safety shoes lighter, toe caps made of a thermoplastic resin reinforced with reinforcing fibers, such as glass fibers, have thus been developed.
As an example of the above-described safety shoe toe cap made of thermoplastic resin, reinforced with glass fibers or other reinforcing fibers, there is that disclosed in Japanese Patent Publication No. 2004-41406A. This publication discloses a safety shoe toe cap, with which the structural form is defined to meet the impact resistance and compression resistance performance requirements stipulated for safety shoe standards in Japanese Industrial Standards JIS T 8101 (grade L, grade S, and grade H standards) and in the unified European Standards, CEN Standards. However, though the fiber reinforced safety shoe toe cap enables a shoe toe cap of thin shape to be manufactured, it is high in manufacturing cost.
Meanwhile, DE200118977U1 discloses an example of a metal-free, fiber-free synthetic resin safety shoe toe cap that is made neither of steel nor of fiber-reinforced thermoplastic resin. This publication discloses a safety shoe toe cap that uses a fiber-free synthetic resin and, by prescribing the structure and the dimensions, meets the impact resistance and compression resistance performance requirements prescribed in safety shoe standards of DIN EN 12568. However, for the safety shoe toe cap of this publication to meet the performance requirements, the respective portions must be made high in thickness and the safety shoe thus becomes heavy. For example, the thickness of a toe portion is 9 to 12 mm (see claim 4 of the same Document). In regard to cost, the material cost is made correspondingly high and the cost is thus high.